Inertia reel



Feb. 2, 1960 H L WALPOLE ET AL 2,923,492

INERTIA REEL 3 Sheets-Sheet 1 Filed May 14, 1956 Feb. 2, 1960 H L. wALPoLE ET AL 2,923,492

INERTIA REEL Filed May 14, 1956 3 Sheets-Sheet 2 Feb. 2, 1960 l H, L WALPOLE ET AL 2,923,492

INERTIA- REEL Filed May 14, 1956 3 Sheets-Sheet 3 www United States Patent INERTIA REEL Harold L. Walpole, Torrance, and Alfred M. Mayo, Palos Verdes Estates, Calif., assignors to Douglas Aircraft Company, Inc., Santa Monica, Calif.

Application May 14, i956, serial No. 586,345v

9 Claims. (C1. 242-1014) This invention relates to automatically locking winding reels especially suitablev for use in conjunction` with safety body harness of the type employed `in vehicles.

The present deviceY represents a departure in structural i detail from, but utilizes several principles of operation of, the invention shown and described in our prior, U.S. Patent No. 2,708,555 issued May 17, 19,55. Y

In general Vthe invention'includes a novel arrangementv of inertia operated means for effecting positive arresting of rotation in at least, one direction of the winding drum portion of atake-up reel. More particularly in its` present form, the inertia operated arresting means includes one or a series of latching pawls adapted to engage a toothed wheel attached to and rotating with the spindle ofthe winding drum. ,Interacting with the pawlsis alinkage system having two operative positions, in the iirst of which the pawls are restrained from engagement with the toothed wheel and in the second of which the pawls are *urgedY` lCel `laat-enten Feb. 2, 1960 2 i Y t Y depict the several operative positions which the partsattain; and

Figure 7 is a perspective view of an aircraft pilots seat showing the relation therewith ofthe reel of the present .invention and attached body harness.

YNow with reference to the drawings, in Figurej7 there is shown, in phantom, a cockpit portion 12 ofran airplane in which is located a pilot seat 14 to which ispattached the lower end of the body harnesslS for positioning about thershoulders of the pilot. To the backj of the seat 14, or other stationary part of the vehicle'body,:is aixed a take-up reel 17. By an internal mechanismherev'inafter described, a short length--eofnylon.webbing 18 or other liexible tension bearingmember such; asia cable e is normally retracted by Yresilient means ,into vthereel 3 17. The free end of webbing'18 connects-to the upper end'of body harness 15 and under the urge of the resilient retracting force the harness 15 will be maintained snugly against the pilots body. The strength of the resilient means A,is readily overcome and, when the reel 17 -isin unlocked condition, normal body motion will withdraw webbing 18. ,Y

n `Leadingaway from and connected to the reel 17 isla Bowden cable 19 havingV anoperating knob 20. at itsremote end conveniently positioned'for manipulation by t the pilot.

Turning now4 to the details ofthe reel 17`in=Figure`11 it is shown that such reel 17 includes composite end plates r and mounting brackets 23 at opposite extremities thereof, such brackets 23: being apertured at 24Yfor the reception of removable screw fasteners by which reel 17 is attached v to the seat 14. Intermediate end plates 23 `is a pairof dividing disks 26, each being-,centrally.journaledat .27

Vfor the reception` of `mainshaft 29. Asa spacerand dust cover a cylindrical sleeve 30 is interposed between dividing disks 26 with' its ends seatedin circular grooves therein. Asl'it 31 inspacer 30 Vallowsipassage of webbing l t 18A into the interior of reel 17. The components Ythus far In summary, the self locking reel includes a rotary spool Y or drum on which a cable or web istwound, a coil spring normally biasing the drum in its windup direction, a ratchet wheel on the drum shaft, inertia actuated pawls and cocking means therefor, and a further pawl manually operated into and out of drum locking position. The

*cable or web free end is adapted for attachment to the body harness and under action of the coil spring serves to continually maintain the harness reasonably tight against the vehicle occupant and yet allows substantial freedom of movement to the occupant. Upon crash impact or any other phenomena causing rapid deceleration of the vehicle the inertia latch is operable to prevent further pay out of the wound cable or web for preventing the vehicle operator or occupant from hurtling forward by his own inertia.

A further feature of the invention resides in the arde ined are maintained in assembled condition by a series of transverse tie bolts 33. v Y WThe previously mentioned webbingl 18v has its inner, end

` affixed to drum or shaft129 andon rotation of suchfl'shaft v29 it will wind on or unwind therefrom, dependingouY -the `directionof the rotation, through slit 31. `Web edgeconlining disks 35 arelocated on shaft 29 at opposite sides t of webbing 1,8 Yand may befree spinning, as here shown,

Vor affixed tothesh'aft 29 for rotation therewith.V These disks 35 are equivalents :of spool flanges and Vserve to reduce or eliminate friction between webbing 18 and reel 17 in winding and unwinding. ,Y

lIn the chamber defined by end plate 23and the adjacent bearing disk 26 -is situated a torsion Vspring 37 inter- Y actingbetween the reel casing and shaft 29 Atonortnally rangement of the cocking cam for the inertia latch and Y means for operating the manual latch whereby at all times when the reel rotation is not prevented bythe manual latch the inertia latch is free to move to locking position.

`Other features of novelty and Vadvantages of construction will become apparent from an understanding of the accompanying drawings in which: A

Figure 1 is a perspective view of the reel with some portions broken away for clarity.

Figure 2 is an exploded view of ratchet wheel and inertia operated pawl portions of the reel; l Y

Figures 3, 4, 5 and 6 are side sectional views of those y reel components of Figure 2 in assembled conditin,` `and wind i'n thewebbing 18.

At the opposite end of the reel 17 is a secondchamber formed by 'theother pair of plates 23 and bearing disks 26 in which is housed the means generally ,designated by numeral 39 for positively braking rotary motion of shaft 29 in the direction in which web 18 unwinds therefrom. It is in the. position and 'details of construction `of, this braking means` 39l that thisinvention vdiffers from ,that disclosed in our above mentioned patent. Y Y

As best seen in Figure 2, the end of shaft 29 has immovably attached coaxially thereto, as by splining, a toothed circular member 40`constituting a ratchet wheel. Above and belowthe axis of rotation of wheel40 are a pair of pawls 42, each pivoted at 43 to bearing disk26. e, Coil spring 44 is interposed betweenone end of each ofpawls Y 42 and fixed posts 45 and at all times urges the associated pawl' 42 into contact with ratchet-'wheel V40. The pawls 42 are so located that they alternately engage the teeth of wheel 40 and the maximum freeV rotation Vof the wheel 40;when the pawls 42 are released by means hereinafter described,` is one Vhalf the` distance between successive teeth. Whilemore or less1 pawls 42 may be used and "tlleirpos'itioninglvaried in Vrelation .to vthe wheel. 40,` our arrangement was elected as a result of a compromise of strength?V requirements and maximum permissible reel travel. when stopping thereof is to be laccomplished. `To

each pawl 42 are respectively pin connected levers 46 and 47vwhichinturn are pivoted to each other at 48, thereby fforminglattoggle joint. The dimensioning of thelevers jointis atidead center i.e. the pivotpoints are aligned, or

`-is slightly on either-side of dead center, the pawls 42"V will `be maintainedont of t locking engagement with ratchet Wheel 40. Y Y 'Y Y t I The force' ofrcoil springs` 44 acting through pawls42 is fheicerted on` thetoggle-joint toV constantly moveit or mainn Y -tland 47 and pivot pointsare such thatwhen the toggle cocked position by means. of the cooking iinger or cam 56.

Although only one preferred embodiment of the present invention is shown and possible alterate constructions suggested, it is to be understoodthat other modications and variations will be apparent and it is intended that the spirit of the invention include suchmodiiications and variations l and be limited only `tothe extent speciedfin the appended claims.V

.We claim: f. Y.

e l. A device of the class described comprising: a rotary drum adapted tohave ,elongatev ilexible tension `bearing means wound thereon;`resilient means normally urging the drum to rotate in a` direction to. wind lthetension bearing means thereon;.a toothed ratchet wheel coaxially ad-` jacent the drum and being connected thereto to rotate therewith; first land i posed above and below a horizontal Vcenterline normal to tain itin one or the'otherof-its over center positions.' In

' the stead of springs'44 a single tension spring (not shown) fbetweenvthe respective. pointsat which levers 46 and 47 {re pivoted to pawls 42 could be usedwith the same` ef f feet-ivgeness.

Y vTo the i'ight, as viewed inrFigure `3, an eccentric 49-is` attached to `endplate 23. This eccentric 497i is situated to bev abutted by the toggle joint in one slightly over center #position and prevent pawls-42 from engagement Vvwith *'at'chet wheel 40. VIn this condition the reel 17 is referred .torsbeing Vin cocked condition. By turning eccentric 49 a change in degree of orf-center of the toggle joint is madeY for purposes hereinbelow explained.V

j "LI`-he Virlassi'or the levers`46 and 47 is of an adequate ex' m'te'nt` vthatluponv a rapid deceleration from ua velocity: in-ja.`

`direction to the left of the reelY as viewed in Figure '3which and below the axis ofv rotation of wheelf40 are a pair of fis the normalvehicle motion direction, the toggle ,joint g moves under the-influence of the mass Yinertia away from pjointftheirate of deceleration `at which the inertia is adelq'ufatejto `throw the joint over lcenter in the locking direc- ^`tion is controlled. In moving to this position the pawls j 42 Yen gagerratchet wheel 40 tolock it thereby preventing Y further pay outofwebbing 18. VInthis manner the *vehicle occupantis restrained by body harness VVfrom beingV thrown forward under his own inertia.

, means out of wheel engagement when the joint is atdead A`contactwith stop49 vacross dead centerland` into the posiio'n'shownnFigure 5. By angularly adjusting the cam stop vw49, thus varying 'the extentof over center of thetoggle to` engage said Vjoint `away from Y l adapted tobe abutted'by said link means when the toggle "joint assumes one slightlyover center position and there` by maintain the pawl `means out `of wheel engagement, the t inertia of` said linkmeans upon rapid` deceleration serving 35- to carry the toggle joint from said oneover center' position means engage ,second direction to maintain the third the axis of a wheel to` prevent movementthereof in a direction in which the Vtension bearing means unwinds.

from the drum; biasing means urging said pawl means into wheel engagement; rst and second -ito'each.other and respectively pivoted torthe first andseclink means pivoted ond pawl means to thereby `constitute a toggle joint, the said link` means beingproportioned to maintain the pawl vcenterorfslightly on either side of dead center, the Abiasing means' urging said pawl means also urging the toggle dead center; adjustable. stop means to its 'opposite over. center position in which the pawl thereof; third pawl'means normally engaging said ratchet wheel;v and manually operable means movable in one direction to forcethe link means into said one over center position and against said stop means,A and movable `in a pawlmeans out of j engagement Vwith said ratchet wheel.

thirdjpawl 52 is pivoted to disk'26 and, as are pawls:

"i742, is urged' to ratchet wheel engagement by compression spring 53.4 vThe spring pressure against paw152 is over come bythe actionof a manually operable, through VBow-Y .lden 'cable L19, lever l55 turning finger 56 which, when lmoved in one direction, 'contacts a pin 57 protruding laterally from pawl 52. When iinger 56 is turned in the other direction and away from'pin 57 Yits cam face moves against "one of thelevers A47 of the'toggle jointV to place the reel in cockedconditio'm i.e.'over center and against stop 49. By

' Imeans urging s aid pawl means utilizing. this commonl means to renderpawl 52 inopera--t ,l

tive andtocock the reel'17, the pilot cannotinadvertently or intentionally defeat the purpose of the assembly. At

:all 'times pawl 5 2 locks `the 'shaft V29 against rotation orY "similar occurrencethe, reel .is automaticallylocked. .jligf ure. 5 Idepicts the reel llocking ,means 39 -a'fterv` actuation effected by Qfleceleration. .lnFigure 6 .thereis fshown .fthe 'relative position 'ofpartstas'the pawls 42 are mQVCd to engagement when the j on either a saidpawlfmeans also urging the Atoggletjoint away from 2l"` A'devic'e of the class described comprising: a rotary drum adapted tou have elongate flexible tension bearing meansfrwound thereonymeans urging the Vdrum to rotate v.in a direction to wind the tension bearing means thereon; a toothed ratchet wheel adjacent the drum and rotatable therewith; pawl Ameans engageahle with said wheel to prevent movement thereof-in a l unwinds from the drum; biasmg direction in which the tension bearing means into wheel engagement; interconnectedlink means pivoted to the pawl means and constituting a toggle joint, the said link means being proportioned Vto maintain the pawlmeans out of Wheel oint is at dead center or slightly side of `dead center, the biasing means urging dead center; stop means adapted 'to be abutted by said llink means whenithe'toggle joint assumes one slightly t overcenter position and `thereby maintain the pawl means outfof wheel engagement; fthe `inertia of -said link means 'upon decelerationservingto carry the `toggle joint from` .-.said,.on`e-over center positiontoits `opposite overcenter j position 3 in ``which the :pawl means .engage the t ratchet wheel and prevent rotation thereof; third pawl Ameans .normally engaging A saidyratchet.vt/heel; manually operable meansmovabledno direction toforce the link rneans into said one over centerposltlon and-againstsaidstop meansnand .movable `in .a second .direction Lt0. .maintain the third pawl means outof. engagement with said ratchet wheel. r

3- A devicen'f.theclassidescribedcomprising artary j drum .adapted'gto .hjaveelorigate flexible .tension .bearing means-.wound .thereotu resilientLmeans .normallyrsing t f'rum f6 'rptte .ili adrection to wind` the tension second Vpawl means respectively vdisrotation of the ratchet wheel and being adapted 4 the `ratchet wheel and prevent rotation l prevent movement thereof in a direction in which the rj,

tension bearing means unwinds from the drum; biasing means urging said pawl means into wheel engagement; irst and second link means pivoted to each other and respectively pivoted to the first and second pawl means to thereby constitute a toggle joint, the said link means being proportioned to maintained the pawl means out of wheel engagement when the joint is at dead center or slightly on either side of dead center, the biasing means urging said pawl means also urging the toggle joint away from dead center; adjustable stop means adapted to be abutted by said link means when the toggle joint assumes onev slightly over center position and thereby maintain the pawl means out of wheel engagement, the inertia of said link means upon deceleration serving to carry the toggle joint from said one over center position to its opposite over center position in which the pawl means engage the ratchet wheel and prevent rotation thereof;

and manually operable means movable in one directionY to force the link means into said one over center position and against said stop means.

4. A device of the class described comprising: a rotary drum adapted to have elongate exible tension bearing means wound thereon; resilient means normally urging the drum to rotate in a direction to wind the tension bear, ing means thereon; a toothed ratchet Wheel coaxially adjacent the drum and being connected thereto to rotatie therewith; first and second pawl means disposed about the ratchet wheel and being adapted to engage said wheel to prevent movement thereof in a direction in which the tension bearing means unwinds from the drum; biasing means urging said pawl means into wheel engagement; first and second link means pivoted to each other and respectively pivoted to the rst and second pawl means to thereby constitute a toggle joint, the said link means being proportioned to maintain the pawl means out of wheel engagement when the joint is at dead center or slightly on either side of dead center, the biasing means urging said pawl means also urging the toggle joint away from dead center; stop means adapted to be abutted by said link means when the toggle joint assumes one slightly over center position and thereby maintain the pawls out of wheel engagement, the inertia of the mass of said link means upon deceleration carrying the toggle joint from said one over center position to its opposite over center position in which the pawls engage the ratchet wheel and prevent rotation thereof; third pawl means normally engaging said ratchet wheel; manually operable means movable in one direction to force the link means into said one over center position and against said stop means, and movable in a second direction to maintain the third pawl means out of engagement with said ratchet wheel.

5. A device of the class described comprising: a rotary drum adapted to have elongate flexible tension bearing means wound thereon; resilient means normally urging the drum to rotate in a direction to wind the tension bearing means thereon; a toothed ratchet wheel coaxially adjacent the drum and being connected thereto to rotate therewith; pawl means disposed to move into engagement with the ratchet Wheel to prevent movement thereof in a direction in which the tension bearing means unwinds from the drum; biasing means urging said pawl means into wheel engagement; a toggle joint cooperating with and maintaining the pawl means out of Wheel engagement when the joint is at dead center or slightly on either side of dead center, the biasing means urging said pawl means also urging the toggle joint away from dead center; and stop means adapted to be abutted by said toggle joint in one slightly over center position and thereby maintain the pawl means out of wheel engagement, the mass of said links serving, upon decelerationthereof, tocarry the toggle joint -from said one overj center position to its oppositeover center position in which `the pawls engage the ratchet wheel and prevent rotation thereof. f

- 6. A device of theV class described comprising: a rotary drum adapted to have elongate ilexible tension bearing means wound thereon; resilient means normally urging the drum to rotate in a direction to wind the tension bearing means thereon; a toothed ratchet wheel connected to the drum and rotating therewith; pawl means'movable into and outA of engagement with Vthe ratchet wheel, and being adapted when in engagement with said wheel to prevent movement thereof in a direction in which the tension bearing means unwinds from the drum; biasing means urging said pawl means into wheel engagement;

a toggle joint cooperating with and maintaining the pawlV means out of wheel engagement when the joint is at dead center or slightly on'either side of dead center, the biasing means urging said pawl means also urging the toggle joint away from dead center; stop means adapted to be abutted by said toggle joint in one slightly over center' Y position and thereby maintain the pawl means out of wheel engagement, the mass of said links, upon deceleration thereof,rserving to carry the toggle joint from said one over. center position to its opposite over center position in which the pawl means engage the ratchetwheel and prevent rotation thereof; other ,pawl means normally engaging said ratchet wheel; manually operable means movable in one direction to force the toggle joint into said one over center position and against said stop means, and movable in a second direction to maintain said other pawl means out of engagement with saidratchet wheel.

7. A device of the class described comprising: means adapted to have a flexible tension bearing element wound thereon; braking means; a member connectedY to the iirst said means and having a surface thereof interlockingly Y engageable with the braking means; anda toggle joint connected to the braking means and being movable between two positions, the toggle joint in `a first of said positions maintaining the braking Ymeans and the member out. of engagement and in a second of said positions urging engagement between the braking means and the member, the toggle joint having adequate mass that upon rapid deceleration thereof n a direction b etweenrthe two positions the inertia of the mass will carry the toggle joint from said first to said second of said positions. Y

8. A device of the class described comprising: means adapted to have a exible tension bearing element Wound thereon; braking means; a member connected to the first said means and having a surface thereof interlockingly engageable with the braking means; a toggle joint connected to the braking means and being movable between two positions, the toggle joint in a first of said positions -mamtaining the braking means and the member out of engagement and in a second of said positions urging engagement between the braking means and the member, the toggle joint having adequate mass that ,upon rapid l deceleration thereof in a direction between the two posi- Vtions the inertia of the mass will carry the toggle joint Y maintaining the braking means and the member out of engagement and in a second of said positions urging engagementgbetween the brakingtmeansand the member,

the toggle joint having adequate mass that upon rapid deceleration thereof in a direction between the two posifrqm the second to the rst said positions 'and' simultan- 

